If you're voting for Brexit because you think British troops will be called up to an EU army, you've been horribly misled

Britain's Eurosceptics have spent years frightening people with the idea of an 'EU army' and the subject is once again rearing its head in the referendum campaign.

Conspiracy-minded Brexiteers insist that, were the UK to stay in the European Union, British troops might soon be faced with conscription into a Brussels-controlled army.

More sober Eurosceptics warn that "the European Union has its sights on NATO". Allegedly designed in the same Brussels and Berlin offices where dreams of an ever closer European union are fostered, this purported European army has become a symbol of EU overreach in one of the most sensitive areas of national sovereignty – defence.

It’s true that a few lofty proposals have been aired in the last 50 years by various member-states and by the most federalist minded among EU elites. Last March, European Commission President Jean-Claude Juncker advocated a common European army as a means to increase the EU’s standing on the world stage, not least in the eyes of Russia. And it has recently been reported that the forthcoming German defence white paper may also propose an EU army in the context of a “defence union”.

But the reality of European defence co-operation does not match the rhetoric. The EU carries out humanitarian and rescue tasks, crisis management and peace-keeping under a common security and defence policy. This does not extend to collective defence of EU territory – nor does any EU government seriously envisage it ever doing so. Nato already plays that role.

NATO Secretary General Jens Stoltenberg has urged Europeans to avoid duplicating the organisation as money invested in an EU army would be money lost for the alliance. In recent years, Central and Eastern European states that see US capabilities as a vital hedge against an aggressive Russia have also expressed their strong preference for Nato. They are unlikely to give up this resistance anytime soon.

In fact, EU member states do not want to cede sovereignty on defence policy at all.  Decisions on defence and foreign policy require unanimity in the Council of Ministers. That means every single EU country has a veto – and that is why David Cameron has rightly referred to the suggestion of an EU army as “fanciful”.

In practical terms, the lack of a shared vision of how to use EU forces would also be an enormous problem in a crisis.

An EU army could only work with a common budget, common institutions, and a supranational defence authority that could over-rule decisions by national parliaments. That is unimaginable to even the staunchest supporter of EU integration.

Some countries enjoy strong collaboration on defence, but integration is only possible because of long-standing ties, shared equipment and similar defence cultures. Without these similarities, integration becomes much more difficult. Such models of cooperation could not be scaled up to a European level.

The political will is simply not there. Paris would rather get the rest of Europe to support French operations in Mali and the Sahel. Ireland secured a protocol to the Lisbon Treaty stating explicitly that the treaty did not provide for the creation of an EU army.

And, importantly, there is also less to Germany's alleged commitment to creating an EU Army than may appear at first sight. It is considered good form for a “good European” in Germany to reaffirm the commitment to a European army – but no one in Berlin is drawing up implementation plans.

It is disingenuous for Eurosceptics to present something that only ultra-federalists dream about in very vague terms as something plausible, let alone imminent and inevitable.

The British people need to decide whether they are better off in or out of the EU as it actually is, and for what it actually does. They should not be pushed vote on an imaginary future hazard.

Invoking the EU army ahead of the referendum is scaremongering at its worst and adds nothing to the real debate we need to have.

Sophia Besch is a research fellow at the Centre for European Reform